Circuit controller



Jan. 16, 1940.

w. c. McWHlRTER 2,187,518

CIRCUIT CONTROLLER Filed Aug. 24, 1937 3 Sheets-Sheet l Jan. 16, 1940.w, c McwHlRTER 2,187,518

CIRCUIT CONTROLLER Filed Aug. 24, 1937 3 Sheets-Sheet 2 Fig.4.

wz'lZzamC. lzrten HIS ATTORNEY Jan. 16, 1940. w. c. McWHlRTER' 2,187,518

CIRCUIT CONTROLLER Filed Aug. 24, 1957 3 Sheets-Sheet 3 VII/II;

INV TOR lUz'lliamm HIS ATTORNEY Patented Jan. 16, 1940 UNITED STATESPATENT orrica CIRCUIT CONTROLLER William (LMcWhirter, Wilkinsburg, Pa.,assignor to'lhe Union Switch & Signal Company, Swissvale, Pa.,a-corporation of Pennsylvania Application August 24, 1937, Serial No.160,641

3 Claims.

.-My inventionrelates to circuit controllers. "Circuit controllersembodying my invention are particularly suitable for, although in no waylimited to, use in connection with slide detector fences of the typewhich are provided along the right of way of railroads 'at locationswhere obstructions to the right of way .due to land or snow slides,falling rocks, falling trees, or the like are likely to occur, tocontrol the usual block or other warning signals in a manner which willcause the signals to give a warning indication in the event that anobstruction occurs, and one object of my invention is to provide a novelcircuitcontroller of the type described which shall be economical :tomanufacture, easy to install, and reliable in operation.

Other objects and characteristic features of my invention will appear asthe description proceeds.

-I shall describe one form of circuit controller embodying my invention,and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is an elevational View illustrating'a circuit controller embodying my invention connected with two adjacentsections of a slide detector fence. Fig. 2

is .a'front view onanenlarged scale of the circuit controller shown inFig. 1, the door of the circuit controller and some of the parts beingremoved, .and some of the parts being shown in section, to betterillustrate-the construction of the remaining parts. Figs. 3 and! aresectional views taken substantially on the lines III'III andIV-IV, re

.spectively of Fig. 2.

Similar reference characters refer to similar :parts-in each of theseveral views.

Referring first to Fig. 1, I have here shown a "circuit controller Aembodying my invention 'operatively-connected with a slide detectorfence such as is commonly-used to protect a railroad .right'of way"through cuts, atthe base of rocky slopes, or at any other locationwhere an obstruction is likely to occur due to land or snow slides,.f-a'lling rocks or "trees, or the like. The fence :may have anypreferred construction'depending upon local conditions, but, as hereshown, the

fence-comprises .two fencesections B and-C, each consisting of a span ofwire I supported :by :end

:posts 2 and 3, and as many-intermediateposts-'4 as the length ofthespan makes necessary or desirable. The end posts 2 and 3 arerequiredto'be iirmly anchored in place, and, for this purpose, the lowerends of theseposts will preferably be embedded in a suitable concretebase or founda- "tion. Furthermore, the end posts 2 may,:if desired, be"braced by other posts 6, the lower ends or repair.

of which are also embedded in concrete. termediate posts 4, however,need not be anchored in place any more firmly than is necessary tomaintain them in upright positions, and these posts will thereforeusually be embedded in the The inearth without providing any specialfoundation. Each span of wire I is rigidly fastened to the associatedend post 2, but is slidably secured to the-end post 3 and to each of theintermediate or decreased. The turnbuckles ID are so ad".

justed, and theparts are so proportioned that the wire I ofthe two spanswill normally be stretched tight,-but that, if either span is struck bya falling object of sufiicient size to cause a dangerous condition inthe-event the object falls onto the right of wayof the railroad, thespan Will deflect and will move the tension-bar toward the associatedend post/3.

The circuit controller A is mounted on an upright post {2 which issecurely anchored to a :rigid foundation I'3 at a location intermediatethe two'tension bars 1, and as best seen in Figs.

2,3, and 4 comprises a suitable housing l5 provided at its forward sidewith a hinged cover t through which access to the operating parts of]the circuit controller may be had for inspection The housing is alsoprovided in its opposite side walls with guideways l5a and b whichslidably receive two trip'rods I1 and I8, and in its bottom wall withopenings #50 and Mid whichslidably receive drop indicators l9 and 25!.respectively. The two trip rods I1 and I8 are operatively connected'bymeans of operating rods Ho and 18a, respectively, with the tension bars1 of the two fence sections B and C in such man- .ner that any movementof the-tension bars caused by lateral displacement of the fence wirewill cause corresponding longitudinal movement of the trip rods. I

A transversely extending rod 2| is mounted in bosses [52 formed in theopposite side walls of the housing l5 above the guideways 15a and i511,and in. forwardly projecting lugs l5 and [5g which are provided on theback wall of the housing i5 op- 'positethetwo bosses l5e, respectively,and pivoted on this rod between the bosses and the lugs are the two arms22a and 22b of a depending U- shaped contact operating member 22. Thecontact operating member is biased, by means of two compressed coilsprings 23a and 23b, to an outer extreme position in which an upwardlyextending stop 220 formed on the'upper end of the arm 22b engages a stoppad i5h formed on the back of the housing, but is adapted to be normallylatched in an inner extreme position by means of latch mechanism which Ishall describe presently. The

coil springs 23a and 232) are interposed between the back wall ofthehousing and laterally projecting ears 22d formed on the arms 22a and22b of the contact operating member 22, and are maintained in the properpositions by suitable guides I52 formed on the back wall of the housingl5 and other guides 22c formed integrally with'the ears 22d.

The latch mechanism in the form here shown comprises a latch arm 24which is pivotally mounted intermediate its ends on a depending stud 25secured to the lower end of the contact operating member 22, and twolatch dogs 26 and 21 which cooperate with the latch arm adjacent itsopposite ends. The latch dogs 26 and 21 are pivotally mounted on atransversely extending rod 28 mounted in bosses I5 and l5k provided inthe side walls of the housing l5 below the guideways EM and Hit, and aremaintained in the proper spaced relation by means of a spacing sleeve 23pinned to the rod. The latch dog 2'! is provided with a cam followerZ'la which cooperates with a cam notchfllib provided in the inner end ofthe trip rod it, and is constantly biased to the position in which thecam follower enters the notch IBbby means of a compressed coil spring3!, one end of which fits into a recess 210 in the latch dog and theother end of which fits into a recess I5m formed in the bottom wall ofthe housing Hi. The latch dog 2B-is similarly provided with a camfollower 26a which cooperates with a cam notch l'lb provided in theinner end of the trip rod I1, and is constantly biased to a position inwhich the cam follower enters the notch l'lb by means of a compressedcoil spring 30, one end of which fits into a recess 250 formed in thelatch dog, and the other end of which fits into a recess I51 formed inthe bottom wall of the housing I5. The latch dog 21 is further providedwith a notch 2Tb which is adapted to at times receive the adjacent endof the latch arm 24, and the latch dog 26 is further provided with anotch which is not visible in the drawings, but which is similar to thenotch 21b in the latch dog 21, and which is adapted to at times receivethe adja cent end of the latch arm 24.

The trip rods'lll and i8 are so adjusted that when the spans of wire Iof the two fencesections B and C occupy the longitudinal positions towhich they are biased by the tensioning connections 8, the notches Nband l8b in these trip rods will align with the cam followers 25a and 21aof the latch dogs 26 and 21; and the parts are so proportioned that ifthe contact operating member 22 is moved to its inner extreme position,by pressing inwardly on the latch arm 24 atlits point of connection withthe operating member when the notches in both trip rods are opposite thecam followers, the ends of the latch arm will automatically enter theassociated notches in the latch dogs'fa'nd will thus latch the operatingarm in its inner extreme position. The parts are further so proportionedthat, if

either trip rod IT or 18 is moved laterally far enough to force theassociated cam follower out of the cam notch when the contact operatingmember is latched in its inner extreme position, as will be the case ifthe wire of the associated fence section is moved laterally by an objectof suiiicient size to cause a dangerous condition provided the objectfalls onto the right of way, the notch in the associated latch dog willmove out of engagement with the latch arm. Both ends of the latch arm 24are rounded, as shown indotted lines in Fig. 4, and the notches in the wtwo dogs 26 and 21 are made somewhat larger than the portion of the armwhich enters the notch, as shown in connection with the notch 2'lblinthe dog 21 in Fig. 3, so that when the notch in either dog moves out ofengagement with the latch arm, the arm will then be free to rotate aboutthe stud 25, without binding inthe notch in the other dog, through asumcient angular distance to permit the. contactoperating member 22 tomove to its outer extreme position, and, as a result, as soon as eithernotch moves out of engagement with the arm the biasing springs 23a and,23b will move the contact operating member to its outer extremeposition. The amount .of lateral movement of the wire of the fencesections necessary to operate the latch mechanism may be varied byvarying the longitudinal positions of the trip .rods I! and 18 with,respect to the associated cam followers to thereby vary the distancethat the triprods must be moved to force the cam followers out of thenotches, which variation may be made at the, point of attachment of theoperating rods Ha and Mia with the tensionbars 1. V The trip rodsv mayhave any desired lengths, but will preferably be of such lengths, that.they will extend only a short distance outside of the controllerhousing, and these rods will preferably be so constructed at their outerends that the operating rods, may be attached to the trip rods by meansof a standardrod jaw and the usual pin and cotter.

Secured to the rear side of the contact,- operating member 2 aretwoqjuxtaposed insulating blocks 32 and 33 between which are clamped thefree ends of a plurality of flexible contact fingers 34, here, shown'asfour in number. Each contact finger 34, cooperates with an associatedcontact member 35 to form a contact 34--35.

Each contact finger 34, and the associated contact member 35 are clampedto the opposite sides of an'insulating block 36 by means of terminalposts 31 and 38, and the insulating block 36,, in turn, is secured tothe previously mentionedlugs l5 and l5g. Each terminal post 3'! iselectrically-connected with the associated contact member 34, but isinsulated from the associated contact finger 35, as will be apparentfrom aninspection of the drawing, while each terminal post 38 iselectrically connected with the associated contact finger 35, but isinsulated from the associated contact finger 34. The parts are soproportion-ed that, when the. contact operating member 22 occupies itsouter position, the

contacts. 34-35 will all be opened, but that,

when the contact operating member occupies its inner position, the,contacts 34-35 will all be closed. -1

It is desirable to provide some means which shall be visible. for somedistance away from the circuit controller. to indicate when the contactoperating-member 22 has been'moved to its outer extreme position duetothe operation of the latch mechanism by one or the other of the triprods 27 and i8, and also to indicate which fence section caused thelatch mechanism to become operated, and it is for this purpose that thepre-- viously referred to drop indicators I9 and 20 are provided. Thedrop indicator i9 is biased by its own weight to a lower position inwhich a stop bar 59a welded to its upper end engages the bottom wall ofthe housing I5 adjacent the slot I50, but is adapted to be normallyretained in an upper position when the cam follower 26a occupies thenotch Ila in the trip rod l1, by means of a latch spring 40 which issecured to the latch dog, and which cooperates with the notch l9bprovided in the indicator. The drop indicator 28 is likewise biased bygravity to drop to a lower position in which a stop bar 20a welded toits upper end engages the bottom wall of the housing 25, but is adaptedto be normally retained in an upper position, when the cam follower 21aoccupies the notch I 8a, by means of a latch spring 4! which is securedto the latch dog 21, and which cooperates with a notch 23b provided inthe indicator. The parts are so proportioned that, when the indicatorsoccupy their upper or latched positions, they will be invisible from theoutside of the housing, but that, when they occupy their lower orindicating positions, the lower ends of the indicators will then projectdownwardly below the bottom wall of the housing far enough to renderthese indicators readily visible for some distance away from thehousing. To insure good visibility of the indicators, they may bepainted any color which contrasts with the color of the housing, suchfor example, as red or white. It will be apparent that, when eitherlatch dog is operated by the associated trip rod, the associated latchspring MB or 4| will be withdrawn from the notch Hb or 20b in theassociated indicater, and will thus permit the indicator to drop bygravity to its indicating position. After an indicator has been droppedto its indicating position, it may be reset provided the associatedlatch dog has then returned to its normal position, by merely liftingthe indicator to its normal position.

The contacts of the circuit controller may be used to control the usualwayside or any other suitable signal in such manner that, when thesecontacts become opened, the signal will display a stop Or cautionindication depending upon the type of control provided. The means forcon trolling the signals by the controller forms no part of my presentinvention, and is, therefore, not shown in the drawings.

The operation of the circuit controller as a whole is as follows:Normally, the trip rods I1 and I8 ocupy the positions in which thenotches l'ia and 18a therein align with the cam followers 26a and 21a inthe dogs 25 and 27, the operating member 22 is latched in its innerextreme position in which the contacts are closed by means of the latcharm 26 and the dogs 26 and 2?, and the two drop indicators 19 and 20 areheld in their upper or non-indicating positions by the springs 4i] and4|. When a slide occurs, the lateral pressure exerted against the fenceforces the wire 1 to move longitudinally through the loose fastenings bywhich it is secured to the associated end post 3 and the intermediateposts 4, and this movement is transmitted through the fence to theassociated tension bar 1, and thence to the associated trip rod, thuscausing the associated trip rod to operate the latch dog controlledthereby. The operation of the latch dog, in turn, trips the latchmechanism and allows the drop indicator controlled by such latch dog todrop by gravity to its indicating position. The tripping of the latchmechanism permits the springs 23a and 23b to move the operating member22 to its outer position in which the contacts 34-45 are open, therebycausing the governing signals to display a stop or caution-indication,as thecase be until the obstruction is removed and the circuitcontroller is reset manually by the maintainer.

Although I have herein shown and described only one form of circuitcontroller embodying my invention, it is understood that various changesand modifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A circuit controller comprising a housing, a contact operating membermounted in said housing for movement between two extreme positions andbiased to one extreme position, contacts in said housing operativelyconnected with said contact operating member, two latch dogs in saidhousing biased to latching positions, means controlled jointly by saidlatch dogs and effective when and only when said .latch dogs both occupytheir latching positions and said contact operating member is moved toits other extreme position for latching said contact operating member inits other extreme position, separate means extending into said housingand cooperating with said two latch dogs respectively for at timesmoving said latch dogs to 'unlatching position, two indicators slidablymounted in said housing for movement between non-indicating positions inwhich said indicators are invisible from the exterior of said housingand indicating positions in which said indicators are visible from theexterior of said housing and biased by gravity to indicating positions,and means controlled by each of said latch dogs for latching a differentone of said indicators in its non-indicating position when and only whenthe latch dog occupies its latching position.

2. A circuit controller comprising a housing, a contact operating membermounted in said housing for movement between two extreme positions andbiased to one extreme position, contacts in said housing operativelyconnected with said contact operating member, two latch dogs in saidhousing biased to latching positions, means controlled jointly by saidlatch dogs and effective when and only when said latch dogs both occupytheir latching positions and said contact operating member is moved toits other extreme position for latching said'contact' operating memberin its other extreme position, separate means extending into saidhousing and cooperating with said two latch dogs respectively for attimes moving said latch dogs to unlatching positions, two indicatorsslidably mounted in guideways provided in said housing and biased todrop by gravity to indicating positions in which the lower ends of saidindicators project out of said housing, each said indicator beingprovided with an opening, and two latch springs secured to said twolatch dogs respectively and. one cooperating with each of said dogs atthe opening in such dog for latching the indicator in a non-indicatingposition when and only when the latch dog occupies its latchingposition.

3. In a circuit controller for slide detector fences comprising acontact biased to an open position, means controlled by a pair of latchdogs they are invisible to indicating positions in which they arevisible, and means controlled by each dog for retaining an associatedone of said indicators in its non-indicating position until the dog isoperated to open said contact, whereby when said contact becomes openedan indication is 5 given of which fence section caused it to open.

WILLIAM C. MCWHIRTER.

